Disk drives typically use heads residing on sliders to read from and write to the magnetic media. Read and write transducers residing in the head are flown at a small, controlled spacing above the magnetic medium (disk) during read and write operations. An air bearing forms between the head and the disk due to the disk rotating at high speeds to provide controlled head to disk spacing. Magnetic fields emanating from the write transducer pole tip switches magnetization of the magnetic medium, i.e., writing to the medium. Among other factors, a smaller and more tightly controlled magnetic writing field will allow more data to be written in the same space, thereby increasing areal density.
FIG. 1 illustrates a side section view of read/write head 100 incorporating a write transducer 150 and read transducer 110, both facing the ABS 190. The read transducer 110 may include shield 111 and shield 113 as well as read sensor 112. Write transducer 150 includes shield 114, main pole 101, assist pole (or auxiliary pole) 101′, coil 140 and coil 140′, leading shield 117 and trailing shield 120. Side shields are not shown in this sectional view, however may reside on the sides of main pole 101. Main pole 101 has trailing bevel 101a and a leading bevel 101b. A leading nonmagnetic gap layer 104 separates main pole 101 from underlying structures, and trailing nonmagnetic gap layer 105 separates main pole 101 from structures above. A nonmagnetic spacer layer 102 is illustrated on the non-beveled section of main pole 101; however, in other embodiments may be provided above main pole 101 beginning at any point distal from the ABS 190, including on bevel 101a. 
FIG. 2 illustrates an ABS view of a read transducer section 200 analogous to read sensor 110 described in FIG. 1. A read sensor 260 is positioned between magnetic bottom shield 250 and magnetic top shield 280 and between side shield 274 and 274′. In one embodiment, nonmagnetic layers 275 and 275′ may be applied above side shields 274 and 274′ respectively. The addition of nonmagnetic layers 275 and 275′ may be desirable to separate a side shield comprising a hard bias from a soft magnetic material in magnetic top shield 280 above. A nonmagnetic gap layer 273 is analogous to nonmagnetic gap layer 105 in FIG. 1.